Method of forming a head assembly

ABSTRACT

Methods of forming a head assembly, a head assembly, and a linear tape drive are provided. One aspect provides a method of forming a head assembly including providing a base member; forming a plurality of head components upon the base member individually adapted to communicate information relative to a tape; providing a plurality of component regions adjacent respective ones of the head components and a path of travel of the tape; and providing a support region intermediate adjacent ones of the head components and positioned to support the tape moving along the path of travel, the support region comprising a material different than a material of the component regions.

This is a divisional of application Ser. No. 09/654,489 filed on Sep. 1,2000, now U.S. Pat. No. 6,639,753 B1, which issued on Oct. 28, 2003, andwhich is hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a method of forming a head assembly, ahead assembly, and a linear tape drive.

BACKGROUND OF THE INVENTION

High capacity storage capabilities are becoming more commonplace anddesired in numerous applications, such as libraries, back-up and archiveconfigurations, for example. It is desired for arrangements to providesuch back-up capabilities without interrupting business operations.Increased speed, accessibility and reliability are additionally desiredfor providing long-term storage of digital data.

The Linear Tape Open (LTO) Ultrium format has been developed as a lineartape format to provide enhanced high capacity storage. First generationconfigurations deliver up to 100 GB of native data capacity on a singlecartridge. Future configurations are believed scalable to providesingle-cartridge native data capacities of 1.6 TB.

Referring to FIG. 1, a convention head configuration 10 for writing andreading data within a high capacity storage device is illustrated. Thedepicted configuration 10 includes a head die substrate 12, filler block14 and cover bar 16. Head elements are provided within a region 18including a plurality of deposited layers and an insulating matrix.Exemplary deposited layers include metallic magnetic materials toprovide write poles, shields and magneto-resistive read elements. Suchis typically deposited upon die substrate 12 and contained between diesubstrate 12 and cover bar 16. The insulating matrix and layerstypically comprise relatively soft materials (compared with thesubstrate and cover bar) due to fabrication methodologies. The softmaterials are susceptible to increased wear compared to other portionsof the head assembly including the substrate 12 and the cover bar 16.

Accordingly, numerous conventional configurations suffer from pole tiprecession wherein the insulating matrix and layers are abrasivelyremoved by a tape passing thereover during use. These conventional headconfigurations are subject to spacing loss in magnetic tape recordingresulting from the pole tip recession. Such spacing loss decreases thedensity of recording capabilities of data upon a given magnetic tape.

Referring to FIG. 2, pole tip recession is illustrated within aconventional head arrangement within region 18. The depictedconfiguration includes AL(1) corresponding to a layer of relatively softmaterial, such as deposited alumina, upon substrate 12. Designation P3corresponds to a shield adjacent a read element (not labeled).Designation P2 corresponds to a shared shield/pole adjacent the readelement. Designation P1 corresponds to a write pole and AL(2)corresponds to a layer of alumina material over the deposited layersforming the head elements. Such heightened susceptibility to pole tiprecession decreases the maximum attainable recording density inconventional devices.

For future increases in linear recording density, there exists a need toprovide improved devices and methodologies having improvements over theprior art devices.

SUMMARY OF THE INVENTION

The invention provides a method of forming a head assembly, a headassembly, and a linear tape drive.

One aspect of the present invention provides a method of forming a headassembly comprising: providing a base member; forming a plurality ofhead components upon the base member individually adapted to communicateinformation relative to a tape; providing a plurality of componentregions adjacent respective ones of the head components and a path oftravel of the tape; and providing a support region intermediate adjacentones of the head components and positioned to support the tape movingalong the path of travel, the support region comprising a materialdifferent than a material of the component regions.

Another aspect of the present invention provides a head assemblyconfigured to communicate information relative to a tape comprising: abase member; and a head member adjacent the base member and comprising:a plurality of head components adjacent a path of travel of a tape andadapted to communicate information relative to the tape; a plurality ofcomponent regions adjacent the path of travel of the tape and respectiveones of the head components; and a support region intermediate adjacentones of the head components and positioned to support a tape movingalong the path of travel, the support region comprising a materialdifferent than a material of the component regions.

Yet another aspect of the present invention provides a linear tapedrive, configured to communicate information relative to a tapecomprising: an input adapted to couple with an external device; acartridge receiving assembly adapted to receive a cartridge including atape; and a head assembly positioned adjacent a path of travel of thetape, the head assembly comprising: a base member; a cover memberadjacent the base member; a head member intermediate the base member andthe cover member and comprising: a plurality of head componentsconfigured to communicate information relative to the tape includingreading information from the tape and writing information to the tape; aplurality of component regions adjacent the path of travel of the tapeand respective ones of the head components; and a support regionintermediate adjacent ones of the head components and positioned tosupport a tape moving along the path of travel, the support regioncomprising a material having a hardness greater than a material of thecomponent regions.

Other features and advantages of the invention will become apparent tothose of ordinary skill in the art upon review of the following detaileddescription, claims, and drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a conventional head configuration.

FIG. 2 is a detailed cross-sectional view depicting a profile of poletip recession of a conventional head arrangement.

FIG. 3 is a perspective view of an exemplary tape drive embodyingaspects of the present invention.

FIG. 4 is a plan view of a first embodiment of a head assembly accordingto aspects of the present invention.

FIG. 5 is a side elevation view of a two bump head assembly embodyingaspects of the present invention.

FIG. 6 is an isometric view depicting details of an exemplary headcomponent.

FIG. 7 is a cross-sectional view depicting a plurality of headcomponents.

FIG. 8 is a cross-sectional view taken along line 8—8 in FIG. 7.

FIG. 9 is a graphical representation of wear of a conventional headassembly.

FIG. 10 is a graphical representation of wear of an exemplary headassembly embodying aspects of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 3, an exemplary tape drive 20 embodying aspects of thepresent invention is illustrated. The depicted taped drive 20 implementsLinear Tape-open (LTO) technology according to the Ultrium format toprovide mass storage capabilities. The Ultrium format is described inRalph Simmons, “HDD Technologies Key to Ultrium Tape”, Data Storage,June, 2000, pp. 25–28, incorporated by reference herein. Such embodimentis exemplary and other technologies or formats may be utilized inaccordance with the present invention. For example, other possibleformats include Digital Linear Tape (DLT) or any helical scan tapeformats utilizing multi-channel thin film heads.

According to the Ultrium format, a magnetic tape utilized for storageand retrieval includes four data bands individually comprising 96 datatracks. Servo bands are provided upon opposite sides of the data bandsof the magnetic tape. Servo bands are encoded with vertical andlongitudinal position information to enable accessing of tracks withinthe data bands.

The illustrated tape drive 20 includes a cartridge, receiving assembly22 adapted to receive a cartridge including media, such as a magnetictape, for data storage and retrieval. Tape drive 20 includes aninput/output device 24 for coupling to an external device for providingdata transfer with respect to tape drive 20. For example, input/outputdevice 24 is coupled with an external device such as a computer, aserver, a storage area network, or other device to provide backup orarchival storage capabilities.

Referring to FIG. 4, an exemplary head assembly 30 of tape drive 20 isdepicted. The illustrated head assembly 30 is referred to as a singlebump head assembly (a double bump head assembly 31 is illustrated inFIG. 5). The illustrated head assembly 30 includes a base member 34, acover member 36, and a head member 38 intermediate base member 34 andcover member 36.

Base member 34 comprises a head chip 40 and a filler block 42 in thedescribed arrangement. Head chip 40 includes a head die substrate 44 andhead member 38 in the depicted configuration. Substrate 44 is providedas a wafer, such as Al₂O₃TiC, and layers are subsequently formed uponsubstrate 44 to form head member 38. Head member 38 may be referred toas a head array in the illustrated embodiment. In the describedexemplary embodiment, layers formed upon substrate 44 comprise analumina matrix and successive layers of metallic magnetic materials toact as write poles, shields and magneto-resistive read elements.Exemplary materials of the poles includes NiFe, FeTaN, or FeAlN. Fillerblock 42 and cover member 36 comprise Al₂O₃TiC in the describedarrangement.

The depicted head member 38 includes a plurality of component regions 46and support regions 48. Head member 38 including component regions 46and support regions 48 are described in detail below with reference toFIG. 7.

Head assembly 30 is typically positioned adjacent to a path of travel ofmedia such as magnetic tape. The path of travel extends in the Xdirection with reference to FIG. 4. Motors (not shown) of tape drive 20are provided to move head assembly 30 in the Y direction to accessvarious data bands of the media passing in X direction. Head chip 40 hasa width (Y dimension) of approximately 8 mm in the described embodiment.

Referring to FIG. 5, the depicted head assembly 31, comprising a doublebump assembly, is illustrated adjacent media 50, such as magnetic tape,moving substantially in the X direction along a path of travel. Headassembly 31 comprises two head assemblies 30 positioned adjacent oneanother in a mirrored arrangement. A layer 53 comprising a shield and aglue is utilized to couple head assemblies 30. Head assemblies 30provide plural bumps 52, 54 individually comprising a plurality of headcomponents (illustrated in FIG. 6 and FIG. 7). According to the Ultriumformat, eight head components are provided within a single one of bumps52, 54. Bumps 52, 54 individually include a read element and writeelement to communicate information with respect to media 50 in oneexemplary, configuration. For example, if media 50 is traveling in adirection to the right, bump 52 may be utilized to write data to media50 while bump 54 is configured to read the just-written track of themedia 50 to verify correct data transfer. Other configurations providebumps 52, 54 including one of a read element or write element.

Referring to FIG. 6, a portion of a head component 60 comprising a writeelement and a read element is depicted. Such are arranged adjacent to adata track 62 of media 50 to communicate data with respect to media 50.In the described embodiment, head components 60 are configured tocommunicate using linear tape-open technology in accordance with theUltrium format. Other configurations of head components 60 are possible.

Structures 64, 71 operate as write poles to impose magnetic flux upondata track 62 to write information thereto responsive to control signalswithin write coils 66. A read element 68, such as a magneto-resistiveelement, is arranged as shown to read data previously written upon adata track. Data read by read element 68 is communicated usingconductors 70. Structures 71, 73 provide magnetic shielding (structure71 operates as a write pole for a write element and as a shield for aread element).

Referring to FIG. 7, component regions 46 adjacent a plurality of headcomponents 60 of head member 38 are shown. Media 50 passes along asurface 72 of head member 38 adjacent respective head components 60.Movement of media 50 is in an X direction (in and out of the drawing)with respect to FIG. 7. Appropriate read and write elements (FIG. 6) ofhead components 60 communicate data with respect to data tracks of media50.

In accordance with aspects of the present invention, support regions 48are provided between or intermediate adjacent component regions 46 andhead components 60. Component regions 46 include a material, such asalumina, about a plurality of layers providing the read and writeelements of head components 60. Component regions 46 and head components60 have a hardness less than substrate 44, filler block 42 and covermember 36.

Referring to FIG. 8, an insulative layer 75, such as alumina, formscomponent region 46 provided about layers of metallization 77 andphotoresist 79 of the depicted head component 60. Component region 46comprises a portion of insulating layer 75 about a single head component60. During usage of tape drive 20, abrasive properties of media 50 wearthe relatively soft insulating material of component region 46 andlayers comprising head components 60.

Referring again to FIG. 7, support regions 48, also referred to aslands, comprise a material different than the material of componentregions 46 and head components 60. Support regions 48 are positioned tosupport media 50 moving along a path of travel adjacent head member 38.According to aspects of the present invention, support regions 48individually have a hardness greater than the materials of the componentregions 46 and head components 60. Support regions 48 have increasedresistance to abrasive wear from media 50. In one exemplary embodiment,support regions 48 comprise Al₂O₃TiC having greater hardness andresistance to wear than component regions 46, comprising material oflayer 75, and head components 60. Over time, support regions 48 exhibitimproved resistance to wear from media 50 and reduce pole tip recession.Support regions 48 reduce deflection of recording tape into componentregions 46 of base member 38. Support regions 48 limit the width of thepole/alumina matrix of component regions 46 presented to media 50.

In the described arrangement, a distance of approximately 330 microns isprovided intermediate middle portions of adjacent head components 60. Adistance Q designates a track vicinity of approximately 30 microns inthe depicted embodiment. It is desired to minimize the distance betweenindividual support regions 48 and the track vicinity to provide enhancedprotection from abrasive wear from media 50. Support regions 48 have asubstantially triangular cross-section in one embodiment.

Additional support regions 74 are also shown elevationally below supportregions 48 in FIG. 7. Support regions 74 comprise the same material assupport regions 48 in one exemplary embodiment and such are utilized toinsure planarity of cover member 36 to base member 34.

Various methodologies are utilized to form support regions 48, 74 inaccordance with aspects of the present invention. Referring again toFIG. 8, head components 60 are formed upon substrate 44. Thereafter,insulating material is blanket deposited as an electrically insulatinglayer 75 over the head components 60 upon substrate 44. Subsequentprocessing includes removing insulating material intermediate adjacenthead components 60 in regions to form support regions 48 shown in FIG.7. A dry etch is utilized in one processing methodology to implementremoval of desired portions of insulating material. An exemplary etchingprocess is chlorine based reactive ion etch. (RIE) if the providedinsulating material is alumina.

According to one fabrication method, cover member 36 is fabricated tohave pillar extensions or teeth which extend outwardly and in a matingpattern to the removed portions of insulating material. Ion milling isutilized in one embodiment to fabricate the appropriate support regions48 upon cover member 36. Thereafter and during fabrication of headassemblies 30, 31, cover member 36 joins or is placed adjacent headmember 38 and the extensions comprising support regions 48 are receivedintermediate appropriate adjacent head components 60.

Alternatively, and following removal of insulating material portions oflayer 75, support region material is deposited over base member 34within the removed portions to form support regions 48. Such istypically subsequent to appropriate masking of head components 60.

Referring to FIG. 9 and FIG. 10, respective graphical representations ofwear of a conventional head assembly and a head assembly according toaspects of the present invention are illustrated. Such representationsdepict wear upon the head assemblies as a function of pressure appliedby the media (e.g., tape) and a wear coefficient corresponding to thematerials of head assembly. Media, such as tape, moves across the headassemblies, from right to left or left to right.

An edge of substrate 12 is depicted in FIG. 9 at approximately −0.135 mmand an edge of cover bar 16 is depicted at approximately 0.135 mm uponthe horizontal axis. Region 18 of the conventional arrangement isdepicted intermediate approximately −0.025 mm and 0.025 mm of the graphupon the horizontal axis.

An edge of substrate 40 is depicted in FIG. 10 at approximately −0.135mm, and an edge of cover member 36 is depicted at approximately 0.135 mmupon the horizontal axis. Head member 38 of the conventional arrangementis depicted intermediate approximately −0.025 mm and 0.025 mm of thegraph upon the horizontal axis.

Referring to FIG. 9, it is illustrated that increased wear occurs acrossthe entire span (from top to bottom) intermediate approximately −0.025mm and 0.025 mm corresponding to relatively soft material of region 18.

Referring to FIG. 10, support regions 48 are provided above 0.30 mm andbelow 0.03 mm upon the vertical axis with a component region 46therebetween. Support regions 48 experience less wear than the componentregion 46 comprising insulating material and the layers forming the headcomponents 60 in the described embodiment and provided intermediate 0.03mm and 0.30 mm. Such also depicts wear within the component region 46increasing from the lower end of region 46 towards a vertical positionof approximately 0.10 mm and from the upper end of region 46 to avertical position of approximately 0.23 mm. It is illustrated to providesupport regions 48 as close as possible to head elements (e.g., poles,shields) of head components 60 within respective component regions 46 toprovide increased resistance to wear.

Aspects of the present invention provide reduced pole tip recessioncaused by wear from media to head assembly 30. Such aspects limitspacing loss enabling increased density recording.

The protection sought is not to be limited to the disclosed embodiments,which are given by way of example only, but instead is to be limitedonly by the scope of the appended claims.

1. A method of forming a head assembly comprising: providing a basemember; forming a plurality of head components upon the base memberindividually adapted to communicate information relative to media;providing a plurality of component regions between respective ones ofthe head components and a path of travel of the media; providing asupport region intermediate adjacent ones of the head components andpositioned to support the media moving along the path of travel, thesupport region comprising a material different than a material of thecomponent regions; and providing an insulating layer and wherein theproviding the support region comprises removing portions of theinsulating layer to form the support region.
 2. The method in accordancewith claim 1 wherein the providing the support region comprisesproviding the support region comprising a material having a hardnessgreater than a material of the component regions.
 3. The method inaccordance with claim 1 wherein the providing the support regioncomprises providing the support region comprising a material having agreater resistance to wear than a material of the component regions. 4.The method in accordance with claim 1 wherein the forming comprisesforming the head components to individually comprise a read element anda write element.
 5. The method in accordance with claim 1 wherein theforming comprises forming the head components to communicate usingLinear Tape Open technology.
 6. The method in accordance with claim 1wherein the providing the support region comprises forming the supportregion upon a cover member and placing the cover member adjacent thebase member.
 7. The method in accordance with claim 6 wherein theforming the support region upon the cover member comprises removingportions of the cover member.
 8. The method in accordance with claim 1wherein the providing the support region comprises depositing supportregion material over the base member.
 9. The method in accordance withclaim 1 wherein the providing the base member comprises providing awafer substrate.
 10. The method in accordance with claim 1 wherein theforming comprises forming head components individually configured tocommunicate digital information relative to the media comprising amagnetic tape.
 11. The method in accordance with claim 1 wherein theproviding the component regions comprises providing the componentregions immediately adjacent to the media moving along the path oftravel.
 12. The method in accordance with claim 1 wherein the providingthe component regions comprises positioning the component regions tocontact the media moving along the path of travel.
 13. A method offorming a head assembly comprising: providing a base member; forming aplurality of head components upon the base member individually adaptedto communicate information relative to media; providing a plurality ofcomponent regions between respective ones of the head components and apath of travel of the media; providing a support region intermediateadjacent ones of the head components and positioned to support the mediamoving along the path of travel, the support region comprising amaterial different than a material of the component regions; wherein theproviding the support region comprises forming the support region upon acover member and placing the cover member adjacent the base member; andwherein the forming the support region upon the cover member comprisesremoving portions of the cover member.